Effects of Ginsenosides on Vasodilator Nerve Actions in the Rat Perfused Mesentery are Mediated by Nitric Oxide

This study was designed to explore the effect of ginsenosides, saponins from Panax ginseng, on the vasodilator nerve actions in the rat perfused mesentery and the mechanism of this effect. In the rat perfused mesentery, when adrenergic nerves were blocked by guanethidine (5 × 10^?6 M) and vascular muscle tone was increased with methoxamine (5 × 10^?6-10^?5 M), transmural field stimulation produced a frequency-dependent vasodilator response, which is due to the release of calcitonin generelated peptide; ginsenosides significantly suppressed this vasodilator response in a concentration-dependent manner (3–30 μg mL^?1). After pretreatment with saponin (50 μg mL^?1, 3min) to damage endothelial cells, this suppressing effect of ginsenosides was unaltered. However, the effect was abolished by N^ω-nitro-l-arginine methyl ester (L-NAME) (10^?4 M), an inhibitor of nitric oxide synthesis and addition of l -arginine (3 × 10^?4 M) restored this suppressing effect. Methylene blue (10^?5 M), an inhibitor of guanylate cyclase, also abolished the suppressing effect of ginsenosides. However, ginsenosides did not alter the relaxation responses caused by exogenous calcitonin gene-related peptide administration. We conclude that ginsenosides can produce an inhibitory effect on the vasodilator response prejunctionally in the rat perfused mesentery and that this effect of ginsenosides may be mediated by nitric oxide released from non-adrenergic, non-cholinergic nerves.     

恶性疟P190抗原保守区Ⅰ、Ⅴ基因的亚克隆及在大肠杆菌中高效表达

作者采用PCR方法克隆了我国海南省FCC1/HN株P190抗原两个保守区基因,分别定名为P190CRI和P190CRV。基因片段经纯化后连接到pUC18载体中进行DNA序列分析,结果显示:除了P190CRV中有5个碱基变换外,其余序列均与MAD20型序列一致。经序列分析的两个基因片段分别与pGEX-2T载体连接,经双酶切鉴定后转化感受态JM109(DE_3)大肠杆菌进行高效融合表达,并且用Sepharose 4B-谷胱甘肽层析柱进行亲和纯化,结果为:两个插入基因片段均得到高效融合表达,经一步亲和纯化后就取得高纯度的重组蛋白。     

高渗盐／甘露醇液对内毒素小鼠脑腺细胞凋亡的保护作用

为探讨高渗盐／甘露醇法（ＨＳＭ）对内毒素诱导小鼠胸腺细胞凋亡的影响，取昆明纯种小白鼠２４只平分为三组，即（１）对照组，腹腔注射生理盐水；（２）内毒素实验组（ＬＰＳ组），腹腔注入内毒素；（３）ＬＰＳ＋ＨＳＭ组，腹腔注入内毒素前后共注ＨＳＭ二次。结果示，第三组胸腺细胞凋亡百分率及ＤＮＡ断裂百分率明显低于第二组（Ｐ〈０．０１），ＤＮＡ断裂碎片中的琼脂糖凝胶电泳未见典型的梯状带。提示ＨＳＭ对内毒素诱导的小     

江油市粮食中霉菌污染调查

对江油市胡豆，黄豆，玉米，大米，麦子，碗豆共３７５件样品进行霉菌污染调查。调查表明：粮食中霉菌平均侵染率８７．８％，其中黄豆，碗豆污染较轻，其侵浸率明显低于小麦，大米，胡豆。胡豆，碗豆，黄豆以曲霉菌属为主；小麦以交链孢霉为主，大米以青霉菌属为主；玉米以预     

大,巨型垂体腺瘤的手术入路选择

自１９９０年以来收治直径在２－５．６ｃｍ的大、巨型垂体腺瘤３３例。依肿瘤生长形态与扩展范围将其简略分为三种类型。Ａ型：瘤体位于鞍内或侵入蝶窦；Ｂ型；瘤体呈椭圆形或哑铃向鞍上扩展，三脑室明显移位抬高；Ｃ型：瘤体巨大侵入三脑室阻塞室间孔或明显的鞍周扩展。     

中国三城市儿童步行者道路交通安全状况回顾性研究

目的了解北京、上海、广州三城市儿童步行安全状况及相关因素,为加强儿童道路交通伤害预防、干预提供科学依据。方法回顾性收集2000~2004年三城市交管部门14岁以下儿童步行者交通伤害发生资料。结果三城市5年间儿童步行者道路交通伤害发生率为14.93/10万,男女比例为1.79∶1,5~9岁为高发年龄,儿童步行者发生道路交通伤、亡的主要责任方为行人,受伤害儿童43.0%为轻伤,46.6%为重伤,10.4%为死亡。结论道路交通伤害严重威胁儿童安全与健康,儿童步行者发生道路交通伤害与多种因素有关,需社会各个部门参与预防。     

Glucokinase and cytosolic phosphoenolpyruvate carboxykinase (GTP) in the human liver. Regulation of gene expression in cultured hepatocytes.

Glucokinase and phosphoenolpyruvate carboxykinase are key enzymes of glucose metabolism in the rat liver. The former is considered to be instrumental in regulating glucose hepatic release/uptake according to the glycaemia level, and cytosolic phosphoenolpyruvate carboxykinase is a major flux-generating enzyme for gluconeogenesis. The level of expression of both enzymes and the regulation of their mRNAs in the human liver cell were investigated. Surgical biopsies of liver from patients undergoing partial hepatectomies and parenchymal hepatocytes derived from the biopsies were used to assay glucokinase, hexokinase and phosphoenolpyruvate carboxykinase activities. Hepatocytes were placed in culture and the actions of insulin, glucagon and cAMP on glucokinase and phosphoenolpyruvate carboxykinase mRNAs were studied. The main results are: (a) glucokinase accounts for 95% of the glucose phosphorylation activity of human hepatocytes, although this fact is masked in assays of total liver tissue; (b) glucokinase activity is set at a lower level in human hepatocytes than in rat hepatocytes, and vice-versa for the gluconeogenic enzyme phosphoenolpyruvate carboxykinase; and (c) as previously shown in rat liver, glucokinase and phosphoenolpyruvate carboxykinase mRNAs are regulated in a reciprocal fashion in human hepatocytes, insulin inducing the first enzyme and repressing the latter, whereas glucagon has opposite effects. These data have interesting implications with respect to metabolic regulation and intracellular hormone signaling in the human liver.     

消炎痛对hCG诱发家兔排卵抑制的形态学研究

应用非甾体抗炎药消炎痛(20mg/kg)抑制hCG 诱发的家兔排卵,注射后的6、9、12、72小时剖腹观察排卵数,并取材进行透射电镜观察和酶组织化学观察。甾体激素合成酶类的组织化学和颗粒细胞内某些细胞器的电镜立体定量学测定结果表明:消炎痛抑制了排卵,却不影响颗粒细胞向黄体细胞的转变。透射电镜观察表明:在排卵前,实验组和对照组最明显的不同是:实验组的外膜和白膜很少见到胶原溶解现象,且表面上皮细胞内含的致密小体不释放其内容物。结果提示:消炎痛主要作用于排卵前卵泡顶部的成纤维细胞和表面上皮细胞,这可能与其抑制了某些与排卵有关的酶的释放有关。     

膝关节盘状半月板损伤患者关节镜术后疼痛的列线图预测模型构建

目的 分析膝关节盘状半月板(DLM)损伤患者关节镜术后疼痛的危险因素,并构建列线图预测模型。方法 收集2017年1月至2021年12月行关节镜手术治疗的217例DLM损伤患者临床资料。依照NRS数字分级法评估术侧膝关节及髌周疼痛情况,将患者分为疼痛组(≤4分,n=26)和非疼痛组(≥4分,n=191)。采用受试者工作特征(ROC)曲线分析获取有统计学意义的连续性变量的最佳截断值。采用多因素logistic回归模型分析DLM损伤患者关节镜术后疼痛的危险因素。构建预测DLM损伤患者关节镜术后疼痛的列线图预测模型,采用校正曲线对列线图预测模型进行内部验证和性能评价,决策曲线对列线图预测模型的预测效能进行临床净收益评估。结果 疼痛组患者年龄、关节软骨损伤比例、术后无冷敷比例均高于非疼痛组(P<0.05),术后负重时间早于非疼痛组(P<0.05)。ROC曲线分析显示：年龄、术后负重时间的AUC分别为0.767、0.774;最佳截断值分别为54岁、7 d。年龄(>54岁)、关节软骨损伤(有)、术后负重时间(≤7 d)是DLM损伤患者关节镜术后疼痛的独立危险因素,术后冷敷(有)是D...     

The role of pioneer neurons in the development of mouse visual cortex and corpus callosum

The primordial plexiform neuropil is very critical to neocortical development. The pioneer neurons, mainly Cajal-Retzius cells in the marginal zone, and subplate neurons in the subplate, differentiate from the primordial plexiform neuropil. In this study, the development of corpus callosum, visual cortex, and subcortical pathways has been observed in C57BL/6 mice with various methods, such as DiI labeling in vitro and in vivo, DiI and DiA in vitro double labeling, immunocytochemistry, and in vivo BrdU and Fast Blue labeling. As early as E14, the primordial plexiform neuropil can be found in the telencephalic wall, and it contains many pioneer neurons. On E15 the primordial plexiform neuropil differentiates into the marginal zone and the subplate. Cajal-Retzius cells exist in the marginal zone, and subplate neurons are in the subplate. Either Cajal-Retzius cells or subplate neurons have long projections toward the ganglionic eminence, suggesting that they migrate tangentially from the ganglionic eminence. Cajal-Retzius cells are involved in radial migration, and subplate neurons participate to guide pathfinding of subcortical pathways. This study reveals how the pioneer neurons, through radial and tangential migration, play an important role in neocortical formation and in the pathfinding of the corpus callosum and subcortical pathways. Furthermore, DiI labeling in vivo has demonstrated the presence of pioneer neurons all along the corpus callosum pathway, especially in the midline. This suggests that pioneer neurons may also play a role in guiding the pathfinding of the corpus callosum. Accepted: 31 July 2001